Hi Aleš, Welcome to EasyEDA. Transformers in EasyEDA can be made using the individual inductors coupled together using the 'K' coupling factor parameter or using the basic ready made Transformer parts in the EasyEDA Libs. The Introductory sheet in the Project below briefly describes the basic ready made parts in the EasyEDA Libs. For more information on how to build transformers using individual inductors and how to set up the parameters of the ready made transformers using coupled inductors, please see the other schematics in this folder. These examples in this project should help you understand how to use them: <https://easyeda.com/project_view_Transformers-and-coupled-inductors_LWewOI0ic.htm> Please note that, just like using a real transformer, you have to set up an input signal source and some sort of load external to the transformer. For more information on sources, please see: <https://easyeda.com/Doc/Simulation-eBook/Introduction-to-using-a-simulator.htm#AllsimulationcircuitsMUSThaveapowerand/orsignalsource> and <https://easyeda.com/Doc/Simulation-eBook/Configuring-Voltage-and-Current-Sources.htm#ConfiguringVoltageandCurrentSources> in our learning resource, the free spice simulation book and tutorials; the EasyEDA Simulation eBook: <https://easyeda.com/Doc/Simulation-eBook/>